The ill effects of light pollution on human’s health and the environment has been acknowledged in many other countries, but the topic is rarely mentioned in Vietnam.

Artificial lights are used in large cities

Phan Phuoc Thai Binh from Phuong Nam Eye Hospital in HCM City said that, if not controlled, light pollution will cause ill effects no less serious than other kinds of pollution.

Light design should always come first before any construction. However, people do not pay attention to this.

Light pollution is understood as the excessive impact caused by artificial lights, mostly at night.

In large urban areas such as Hanoi and HCM City, artificial lights, most of which are LED lamps, are used in entertainment complexes, buildings and signboards.

Light stimulates body activities, and helps people stay conscious. The sunlight, for example, wakes people up and increases the heart rate.

However, if light is active at night, when human eyes are in a state of rest, it will cause negative effects. Looking at artificial light will inhibit the production of melatonin (a form of hormone that maintains the circadian rhythm) of the eye.

Artificial light has an impact on the retina, and damages pigmented epithelial cells nourishing the retina. Decreased pigmented epithelial cells cause degradation of eyesight. This can cause blindness in the elderly due to macular degeneration.

The scientific research so far has not discovered the time and intensity of light at which eyes will be affected. People are advised use light within the range of 300-400 lux. If they use light during work and keep the light intensity at a high level, they will feel tired as eyes cannot adapt.

People are also advised not to look at the screens of TV and electronic appliances, smartphones and tablets for too long.

Also according to Binh, there is no scientific research which confirms that blue light can cause cancer. However, studies all show that such light suppresses the secretion of melatonin, thus causing the body to stay awake and weaken the immune system.

Light pollution also has big impact on the living environment. Research in environmental fields shows that plants do not grow well with excessive artificial light. Animals such as owls and bats move to other areas to live when the light is too bright. Migratory birds often fly at night. Birds can feel disoriented and collide with high buildings.